RTComm doesn't support TLS etc just yet and i fear this bug is with RTComm rather than OpenVPN (just guessing, i hope not)... though, in the mean time, i have found a pretty elegant solution (when i'll manage to figure out why i can't get it to work yet ;-) with OpenSSH 4.3 and later with a kernel supporting TUN/TAP devices. You can use ssh -w any:any your.host.com to generate a tunX device through which you can route traffic... no need for additional VPN softwares anymore :-D

a couple references for futur use:
http://www.debian-administration.org/articles/539
https://help.ubuntu.com/community/SSH_VPN